﻿/* 
 * PROJECT: NyARToolkitCS(Extension)
 * --------------------------------------------------------------------------------
 * The NyARToolkitCS is C# edition ARToolKit class library.
 * Copyright (C)2008-2009 Ryo Iizuka
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 * 
 * For further information please contact.
 *	http://nyatla.jp/nyatoolkit/
 *	<airmail(at)ebony.plala.or.jp> or <nyatla(at)nyatla.jp>
 * 
 */
using System;
using System.Collections.Generic;
using System.Text;
using System.Diagnostics;

namespace jp.nyatla.nyartoolkit.cs.core
{
    /**
     * 平滑化フィルタ
     * Gaussianフィルタで画像を平滑化します。
     * カーネルサイズは3x3です。
     */
    public class NyARRasterFilter_GaussianSmooth : INyARRasterFilter
    {
	    private IdoFilterImpl _do_filter_impl; 
	    public NyARRasterFilter_GaussianSmooth(int i_raster_type)
	    {
		    switch (i_raster_type) {
		    case NyARBufferType.INT1D_GRAY_8:
			    this._do_filter_impl=new IdoFilterImpl_GRAY_8();
			    break;
		    default:
			    throw new NyARException();
		    }
	    }
	    public void doFilter(INyARRaster i_input, INyARRaster i_output)
	    {
		    Debug.Assert (i_input!=i_output);
		    this._do_filter_impl.doFilter(i_input,i_output,i_input.getSize());
	    }
    	
	    interface IdoFilterImpl
	    {
		    void doFilter(INyARRaster i_input, INyARRaster i_output,NyARIntSize i_size);
	    }
	    class IdoFilterImpl_GRAY_8 : IdoFilterImpl
	    {
		    public void doFilter(INyARRaster i_input, INyARRaster i_output,NyARIntSize i_size)
		    {
			    Debug.Assert (i_input.isEqualBufferType(NyARBufferType.INT1D_GRAY_8));
			    Debug.Assert (i_output.isEqualBufferType(NyARBufferType.INT1D_GRAY_8));
			    int[] in_ptr =(int[])i_input.getBuffer();
			    int[] out_ptr=(int[])i_output.getBuffer();
			    int width=i_size.w;
			    int height=i_size.h;
			    int col0,col1,col2;
			    int bptr=0;
			    //1行目
			    col1=in_ptr[bptr  ]*2+in_ptr[bptr+width  ];
			    col2=in_ptr[bptr+1]*2+in_ptr[bptr+width+1];
			    out_ptr[bptr]=(col1*2+col2)/9;
			    bptr++;
			    for(int x=0;x<width-2;x++){
				    col0=col1;
				    col1=col2;
				    col2=in_ptr[bptr+1]*2+in_ptr[bptr+width+1];
				    out_ptr[bptr]=(col0+col1*2+col2)/12;
				    bptr++;
			    }			
			    out_ptr[bptr]=(col1+col2)/9;
			    bptr++;
			    //2行目-末行-1

			    for(int y=0;y<height-2;y++){
				    //左端
				    col1=in_ptr[bptr  ]*2+in_ptr[bptr-width  ]+in_ptr[bptr+width  ];
				    col2=in_ptr[bptr+1]*2+in_ptr[bptr-width+1]+in_ptr[bptr+width+1];
				    out_ptr[bptr]=(col1+col2)/12;
				    bptr++;
				    for(int x=0;x<width-2;x++){
					    col0=col1;
					    col1=col2;
					    col2=in_ptr[bptr+1]*2+in_ptr[bptr-width+1]+in_ptr[bptr+width+1];
					    out_ptr[bptr]=(col0+col1*2+col2)/16;
					    bptr++;
				    }
				    //右端
				    out_ptr[bptr]=(col1*2+col2)/12;
				    bptr++;
			    }
			    //末行目
			    col1=in_ptr[bptr  ]*2+in_ptr[bptr-width  ];
			    col2=in_ptr[bptr+1]*2+in_ptr[bptr-width+1];
			    out_ptr[bptr]=(col1+col2)/9;
			    bptr++;
			    for(int x=0;x<width-2;x++){
				    col0=col1;
				    col1=col2;
				    col2=in_ptr[bptr+1]*2+in_ptr[bptr-width+1];
				    out_ptr[bptr]=(col0+col1*2+col2)/12;
				    bptr++;
			    }			
			    out_ptr[bptr]=(col1*2+col2)/9;
			    bptr++;
			    return;
		    }
	    }
    }
}
